Roger Federer underwent a medical examination last week after his fourth round US Open loss to John Millman. It was a very humid night and in his press conference, the Swiss player admitted there was no circulation of air on the roofed Arthur Ashe Stadium.

Anyway, Federer has quickly recovered from that difficult night, the Swiss player's coach Severin Luthi said as quoted by the journalist Simon Graf. Federer is still staying in the United States and from 21st to 23rd September, he will play the Lager Cup in Chicago.

In an interview to Nau, Luthi added: 'Roger is doing fine! Of course, one is disappointed if you don‘t achieve what you wanted, so you try to improve and do things differently the next time, he‘s preparing for the Laver Cup and very much looking forward to it.' Meanwhile, the former world no.

4 and former Wimbledon semi-finalist Tim Henman commented on Federer's statements following the loss to Millman. 'When you hear the dialogue that's coming from the players and someone like Federer saying he got to the stage where he was happy the match was over, then that raises alarm bells for me.

I've always been against the heat rule because I feel the physicality is an important part of a player's armoury, and the ones that have prepared better, trained better, will reap the rewards' Henman said.